Method of producing slub yarns



March 8, 1960 w s 2,927,417

METHOD OF PRODUCING SLUB YARNS Filed Feb. 28, 1958 INVENTOR #971587"? J.Woods MW-F ATTORNEYS METHOD or pnonucmo SLUB YARNS Herbert J. Woods,Greensboro, N.C., assignor to Burlington Industries, Inc., Greensboro,N.C., a corporation of Delaware Application February 28, 1958, SerialNo. 718,195

8 Claims. (Cl. 57-156) This invention relates to the production of yarnand more particularly to an improved method of producing novelty yarn,such as yarn having slubs of random length at random intervals therein.

Random slub yarn is well-known and is presently pro duced on spinningframes provided with mechanical means, controlled either mechanically orelectrically, which cause speed changes in one or more of the draftingrolls of the spinning frame to thereby induce or cause to be producedslubs, of irregular length and spaced as irregularly as possible, in theyarn. While the present spinning frame machinery spaces the slubs in theyarn as irregularly as such mechanical means will permit, such meansinherently tends to produce a slub pattern in the yarn which isperiodically repeated. That is, present slub yarn producing equipmentbeing necessarily actuated by mechanical or electrical means isinherently cyclical in operation. For example, a rotatable member suchas a wheel cylinder, endless belt or endless chain with irregularlyspaced links or pins for actuating clutches to interrupt the drive tothe drafting rolls, must necessarily make one revolution and start againfrom the beginning point of the cycle.

Slub yarns in which the slub pattern is periodically repeated have thedisadvantage that when the yarn is woven into fabric, the slubs alignthemselves into geometric patterns which are repeated throughout thefabric. Thus, the desired random textured effect in the fabric isdetrimentally effected.

There have been many proposals for producing a slub yarn in which theslubs are infinitely random, however none of these proposals have provenentirely satisfactory. For example, some devices now in use employ tworotatable members with irregularly disposed pins on each and mechanicalor electrical means is provided to actuate the clutch alternately fromone to the other to thereby break up the cyclic aspect of operation.While this arrangement tends to extend the total cycle, nevertheless it.is not truly non-cyclic and the resulting fabric does show .to someextent a repeating pattern.

Another proposal is the utilization of multi-shuttle or mixed motionweaving with slub yarns having cyclic .slub patterns therein which, tosome extent, breaks up the cyclic effects of the fabric produced. Thisarrangement is quite cumbersome and renders the weaving opera- :t'ionconsiderably more expensive and difficult.

It has also been proposed to actuate the drafting roll clutches by anaturally occurring random phenomenon. For example, cosmic rays or radiowaves which produce truly infinite random pulses which can be utilizedto ultimately effect the operation of the clutches in response to thepulses. This proposal has the disadvantage that the equipment necessaryis considerably expensive and is quite delicate in operation.

The present invention contemplates the provision of a simple procedurefor producing novelty yarn having slubs therein of random length and atrandom intervals which overcomes the disadvantages noted above. In

ning frame.

927,417 Patented Mar. 8, 1960 general, it has been found that thesedisadvantages can be overcome by initially producing the slubs in aplurality of rovings which are subsequently used to make up the yarnrather than in the yarn itself on the spin- The plurality of slubbedrovings are subsequently drafted and spun together with the result thatthe yarn has slubs which are of random length and disposed at randomintervals throughout.

With this procedure, repeating slub patterns, which may be present intheslubs of the individual rovings, are broken up during the draftingand spinning of the two slubbed rovings together. For example, two slubsin two rovings may arrive between the drafting rolls coterminally, thatis, end to end in parallel relationship, or conjunctively, that is, endto end one following the other or they may arrive separately with aninterval of time ensuing. They may also arrive overlapped to any degreefrom percent which would be co-terminal or zero percent which would beconjunctive. In this manner, infinite variation is accomplished bychance and not by predetermined course, and there is not and can not bea return to the point of beginning. This lack of periodicity is furthercomplicated by the fact that two or more rovings, due to the differencesin tension and small inch to inch variations in their diameter, do notenter the drafting zone with precisely the same linear speed.

Accordingly, it is an object of the present invention to provide amethod of producing slub yarn in which the slubs are of random lengthand at random intervals throughout and are devoid of any cyclic patternso that the resulting fabric woven therefrom will not contain slubpatterns therein.

The present method readily lends itself to many interesting anddesirable variations which make possible the production of novel yarnwhich can be utilized to produce varied effects in the fabric woventherefrom. For example, one roving can have long, thin slubs and theother or others short, thick slubs thus resulting in widely varyingeffects in the final yarn and resulting fabrics. Moreover, the rovingsmay be of different material, for example, one may be of viscose and theother or others of acetate which would result in a varying effect in thefinal yarn and fabric. Furthermore, one or more of the rovings may bepredyed or solution-dyed a different color from the other or others withrandom effects being thus obtained. For example, if two rovings areutilized and one is dyed black and the other white, the final yarn willhave white slubs, gray slubs, and black slubs irregularly disposed inthe yarn and in the resulting fabric.

Accordingly, another object of the present invention is the provision ofa method of producing slub yarn of the type described which readilylends itself to simple variations so that the resulting yarn and fabricare provided with interesting and novel effects.

These and other objects of the present invention will become moreapparent during the course of the following detailedvdescription andappended claims.

The invention may best be understood with reference to the accompanyingdrawings wherein an illustrative embodiment is shown.

In the drawings:

Figure 1 is a schematic view illustrating the manner in which the fiberstock is drafted and twisted to form a slubbed roving; and

Figure 2 is a schematic view illustrating the manner in which twoslubbed rovings produced as illustrated in Figure 1 are drafted and spuntogetherto produce the random slubbed yarn.

Referring now more particularly to Figure 1 of the drawings, a fiberstock such as slivers or a roving 10 wound about a bobbin or the like ispassed between three pairs of spaced drafting rolls 12, 14 and 16. Thedrafting rolls are of conventional construction and preferably are ofthe type normally utilized on a conventional roving frame. Anyconventional means for varying the rotative speed of the pairs ofdrafting rolls relative to one another may be provided. Sucharrangements utilized on a conventional spinning frame are well-knownand usually embody clutches and irregular cams arranged to actuate theclutches at predetermined intervals throughout a cycle of operation.From the drafting rolls where slubs are formed in the stock, the latteris fed to a conventional twister head 18 Where the slubbed stock isgiven a slight twist in accordance with usual practice and finally woundaround a bobbin 20. i v m The slubbed roving contained on the bobbin 29and produced as indicated above has slubs formed therein which have aperiodically repeated pattern. iAs noted above, the present inventioncontemplates the snbsei uent drafting and spinning together of two ormore of such slubbed rovings to produce the final yarn. Q i

Referring now more particularly to Figure 2, two bobbins of slubbedroving 22 and 24 are suitably mounted so that the rovings are ledtherefrom and passed between three pairs of spaced cooperating draftingrolls 26, 28 and 30. Preferably, the drafting rolls 26, 28 and 30 are ofthe type normally provided on a conventional spinning frame and eachpair of cooperating drafting rolls is maintained at a constant rate ofrotative speed. The two slubbed rovings pass through the drafting rollsand are directed to a conventional ring spinner 32, as by a pigtailguide 34 or the like, where the drafted rovings are spun together toform yarn and wound around a bobbin 36. I

As illustrated in Figure 2 the rovings 22 and 24 which are passedtogether through the drafting rolls 26, 28 and 30 are each formed in themanner shown in Figure 1. Thus, each roving has slubs formed thereinwhich have a periodically repeating pattern. However, since they aredrafted together between the rolls 26, 28 and 30 the periodicity of eachof the rovings is broken up. For example, it will be noted that twoslubs in the rovings may arrive between the drafting rolls 26co-terminally, in ofiset overlapping relation, conjunctively, or inspaced relation. In this manner infinite variation in the resulting yarnis accomplished by chance and not by predetermined course so that thereis not and can not be a return to a beginning point. This lack of arepeating pattern is further complicated or enhanced by the fact thattumor more rovings, due to differences in tension and small inch by inchvariations in their diameters, do not enter the drafting zone withprecisely the same linear speed.

While the-two rovings shown in Figure 2 are disclosed as being producedon the same roving frame and thus have similar cyclically repeated slubpatterns, it is possible to utilize more than two such rovings and tovary the slub pattern of the rovin gs utilized. Extremely wide variationin the size of the slubs in the final yarn will result depending uponthe size of the slubs in the rovings 22 and 24' and their arrangement inthe roving whether regular or irregular. Thus, one roving can have long,thin slubs and the other or others short, thick slubs resulting inwidely varying effects in the final. yarn and resulting fabrics.

Another effect possible with the present method is that the stock usedto make the two or more rovings can be of different material so that theresulting yarn drafted and spun from the rovings of different materialwill likewise produce an interesting and novel effect. For example, oneroving may be of viscose and the other or others of acetate. Thisparticular arrangement is significant since the two materials dyedifferently, such as black and white, so that the resulting yarn willhave white slubs, gray slubs, and black slubs irregularly disposedtherein. In this regard any one of the rovings or all may be predyed orsolution dyed a different color fromkthe other or others withinteresting and novel effects obtained in the resulting fabrics.

From the above, it can be seen that the present method is effectivetoproduce a yarn having slubs therein which are truly of random lengthand disposed at true random intervals without a repeating pattern or thelike. The production of an infinitely random slubbed yarn is quiteimportant since the resulting fabric woven therefrom presents adesirable random appearance rather than one in which the slubsformgeometric patterns therein which are repeated along the length ofthe fabric. Thus, the present invention eliminates the necessity ofweaving with multi-shuttles or mixed motion such as is the currentpractice in order to break up to some degree the cyclic effects in slubyarns which are not infinitely random. Moreover, because the slubs whichare ultimately formed in the yarn are produced on the roving framerather ha e innin rame a a see ers the Practice,

' ma mum sp nin s ed? .caa' l t l s be underuse tha Where h s e 9 ied-rai r011S in a spinning frame are periodically varied it becomes necessary to reduce the frame speedin order to allow for the inertia ortorque of the actuating clutches and in some cases slower speeds arenecessary due to the possibility of clutch tooth failure.

It thus will be seen that the objects of this invention have been fullyand effectively accomplished. It will be realized, however, that theforegoing specific embodiment has been shown and described only for thepurpose of illustrating the principles of this invention and is subjectto extensive change without departure from such principles. Therefore,this invention includes all modifications encompassed within the spiritand scope of the following claims.

I claim:

1. A method of producing yarn having slubs of random length at randomintervals which comprises the steps of producing a plurality of rovingseach having slubs formed therein and then drafting and spinning theplurality of slubbed rovings together to produce a slubbed yarn.

2. A method of producing yarnhaving slubs of random length at randomintervals which comprises the steps of drafting a first fiber stockbetween spaced rolls while varying the roll speed to produce slubs andforming therefrom a first slubbed roving, drafting a second fiber stockbetween spaced rolls while varying the roll speed to produce slubs andforming therefrom a second slubbed in nd then draf in and singin thfirst and Second lubbed ro n t th r- 3. A method as defined in claim 2wherein the first n wn fibe $1 9 2 a ra di e ma e a 4. A method asdefined in claim wherein the first and second slubbed rovings are .dyeddifferent colors prior to their drafting and spinning'together.

5. A method of producing yarn having slubs of random length at randomintervals which comprises the steps of passing a first fiber stockbetween spaced pairs of drafting rolls, periodically varying the speedof the drafting rolls to form slubs in the first fiber stock, formingthe slubbed first stock into afirst slubbed roving, passing a secondfiber stock between spaced pairs of drafting rolls, periodically varyingthe speed of the drafting rolls to form .slubs in the second fiberstock, forming the slubbed second stock into a second slubbed roving,passing the first and second slubbed rovings together be tween spacedpairs of drafting rolls while maintaining the speed of the rollsconstant, and then spinning the drafted together first and secondslubbedrovings together to form a slubbed yarn.

6. A method as defined in claim, 5 wherein the periodical varying of thespeed of the drafting rolls to form slubs in the first fiber stock isdifferent from the periodical i g f a sp f th su ing @11 1 ism slubs 5 Vin the second fiber stock whereby the slab size and interval of eachslubbed roving is difierent.

7. A method as defined in claim 5 wherein the first and second slubbedrovings are dyed different colors prior to their passage togetherbetween the drafting rolls.

8.- A method as defined in claim 5 wherein the first and second fiberstocks are of different material.

UNITED STATES PATENTS Young Oct. 28, 1913 Nigrin et a1 July 23, 1929Homer Feb. 2, 1937 Byers June 7, 1949

